This application claims, under 35 USC 119, priority of Japanese Application No. 2000-326764 filed Oct. 26, 2000.
1. Field of the Invention
The present invention relates to a plug for a fluid pipe connector, which is used for connecting fluid pipes to each other or for connecting a fluid pipe to a storage tank, a processing unit or the like.
2. Description of the Prior Art
Fluid pipe connectors for connecting a fluid pipe for flow of chemicals to a storage tank, a processing unit or the like, generally have a flange structure. As shown in FIG. 2, such a fluid pipe connector 1 comprises, on one side, a connecting portion 3 which is provided on an end portion of a fluid pipe 2 on the side of a storage tank, and a connecting portion 5 on the other side which is provided on a plug body 4. The one side connecting portion 3 and the other side connecting portion 5 are provided with fixing flanges 6 and 7, respectively. The fixing flanges 6 and 7 are fixed to each other by means of bolts 8, so that the fluid pipe 2 is connected to the plug body 4.
In order to carry chemicals safely, the fluid pipe 2 comprises an inner tube, an intermediate tube and an outer tube, wherein the outer tube is formed of stainless steel. Accordingly, the fluid pipe 2 has a considerably heavy weight.
Because the fluid pipe 2 is heavy, the connection of the one side connecting portion 3 to the other side connecting portion 5 tends to loosen. That is, there is a problem in that the weight of the fluid pipe 2 tends to force the upper sides of the fixing flanges 6 and 7 apart, to loosen the connection.
It is therefore an object of the present invention to eliminate the aforementioned problems and to provide a plug for a fluid pipe connector, which plug is capable of supporting a heavy fluid pipe in a manner providing a secure connection of the fluid pipe to another fluid pipe, a storage tank, a processing unit or the like.
In order to accomplish the aforementioned and other objects, according to one aspect of the present invention, there is provided a plug for a fluid pipe connector for connecting fluid pipes to each other or for connecting a fluid pipe to a storage tank or a processing unit, the plug comprising: a plug portion, the rear portion of which is fixed and the front of which is open for discharge of a liquid; a fixed plate which is formed as a flange on an end of a fluid pipe; a fixing portion for sandwiching the fixed plate portion between the fixing portion and a base end portion of the plug portion to fix and support the fixed plate portion; a cylindrical supporting portion which is integrally provided on the fixing portion for loosely supporting the fluid pipe; and a fixing nut for covering and fixing the plug portion and the fixing portion.
Since the plug portion and the fixing portion are fixed and covered by the fixing nut, the plug for fluid pipe connector can be miniaturized and easily handled. In addition, since the fluid pipe is loosely supported on the cylindrical supporting portion, the fluid pipe does not bend at an acute angle. Moreover, the fluid pipe is supported on the cylindrical supporting portion to prevent the fluid pipe from greatly canting at the connection of the fixed plate portion which is sandwiched between the plug portion and the cylindrical portion, so that it is possible to reliably prevent this portion from canting.
The plug for a fluid pipe connector is preferably provided with longitudinal sections of different outer diameters to provide an engagement surface for a locking mechanism in the form of an annular shoulder therebetween.
With this construction, the locking mechanism can reliably engage the outer periphery of the plug, so that it is possible to reliably fix the plug to the mating portion of the fluid pipe connector.
The plug further comprises a valve at its distal end, the valve opening to establish fluid communication when the valve is pushed into a member to be fixed thereto. With this construction, the plug portion is not open unless the valve contacts and pushes against the member which is to be connected thereto. Thus, safety in handling is improved.
The plug preferably further comprises a longitudinal groove for preventing the plug from being erroneously mounted, the long groove being formed in the outer peripheral surface of the fixing nut. With this construction, the plug of the fluid pipe connector can not be inserted into a member which is to be connected thereto, unless the long groove is aligned with the member which is to be connected thereto, thereby preventing improper mounting.
An enlarged diameter portion to be engaged by the fixing nut is preferably formed on the base end of the plug portion. With this construction, the fixing nut engages the enlarged diameter portion of the base end portion of the plug portion to fix the plug portion to the cylindrical portion.
An O-ring for sealing a fluid passage is preferably provided on an end face of the enlarged diameter portion. With this construction, the fluid passage is surely sealed by the O-ring when the plug is fixed.
The plug preferably further comprises a locking nut which pressingly contacts the fixing nut for preventing the fixing nut from rotating and thereby loosening. With this construction, the locking nut surely prevents the loosening of the fixing nut.
An annular groove, for engagement by a locking mechanism to be fixed, is preferably formed in and around the outer periphery of a central portion of the plug portion.
The plug portion is preferably cylindrical, the distal end of the plug portion being provided with an opening, and preferably includes a valve for opening and closing the opening. With this construction, fluid communication through the opening at the distal end of the plug is open and closed by the valve.
The valve for opening and closing the plug opening is preferably provided with a communication hole which establishes fluid communication when spaced from a valve seat in the plug, and with an opening and closing protrusion for pushing a member, which is to be connected to the plug, to separate the valve from the seat valve. With this construction, the opening and closing protrusion of the valve pushes the member, which is to be connected to the plug, to separate the valve from the seat valve, and in this state, fluid communication is established through the communication hole.
According to another aspect of the present invention, there is provided a plug for a fluid pipe connector for connecting fluid pipes to each other or for connecting a fluid pipe to a storage tank or a processing unit, the plug comprising: a plug portion which is fixed at one end and opens at an opposite, distal end from which a liquid is discharged, the plug portion having a thread around its outer periphery. A fixed plate is formed as a flange of a fluid pipe. A fixing element with internal threads is screwed onto the plug portion for sandwiching the fixed plate between a fixing portion and an end face of the plug portion. A cylindrical support is integrally formed with the fixing portion for supporting the fluid pipe. With this construction, the fixing element is screwed onto the thread of the plug portion to fix the fixed plate of the fluid pipe, so that it is possible to decrease the number of parts and the outside diameter of the plug for fluid pipe connector.